docs: def _get_choices(self, gandi):
          """ Internal method to get choices list """
          image_list = []
          for item in gandi.image.list():
              label = item['label']
              if item['visibility'] == 'deprecated':
                  label = '*%s' % label
              image_list.append(label)
          disk_list = [item['name'] for item in gandi.disk.list_create()]
          return sorted(tuple(set(image_list))) + disk_list